Non-clogging type blast device



R. G. MILLHISER ETAL 3,374,581

NON-CLOGGING TYPE BLAST DEVICE March 26, 1968 6 Sheets-Sheet 1 FiledJune 14, 1966 March 26,. 1968 R. G. MILLHISER ETAL 3,374,581

NON-CLOGGING TYPE BLAST DEVICE 6 .Sheecs-Shee v Filed June 14, 1966IHIIH WW I March 26, 1968 Filed June 14, 1966 llmm i R. G. MILLHISERETAL NON-CLOGGING TYPE'B LAST DEVICE 6 Sheets-Sheet 5 M VW March 26,1968 R. G. MILLHISER ETAL 3,

NON-CLOGGING TYPE BLAST DEVICE Filed June 14, 1966 6 Sheets-Sheet 4 Jim.

HUIIH BY M, V

March 26, 1968 G. MILLHISER ETAL 3,374,

NON"CLOGGING TYPE BLAST DEVICE 6 Sheets-Sheet 5 Filed June 14, 1966.

VIIIIIIIIIIIIIIIIF NVENTORS Mill /5f Iggy 70M? C. 1404465? M W ATTORNEYSMarch 26, 1968 R. G. MILLHISER ETAL 3,374,581

NON-CLOGGING TYPE BLAST DEVICE Filed June 14, 1966 6 Sheets-Sheet 6INVENTORS. ROBERT G. MILLHISER RAYMOND C.WINGER ATTORNEYS United StatesPatent O 3,374,581 NON-CLOGGING TYPE BLAST DEVICE Robert G. Millhiser,Detroit, and Raymond C. Winger, Livonia, Mich, assignors to AjenLaboratories, Inc., Livonia, Mich. Continuation-impart of applicationSer. No. 394,198, Sept. 3, 1964. This application June 14, 1966, Ser.No. 562,420

6 Claims. (Cl. 51-8) ABSTRACT OF THE DISCLOSURE A non-clogging nozzlefor liquid grit blasting useful for making minor adjustments indirection of blasts from fixed grit blasting devices and also inconverting a spaced series of blasts into a continuous ribbon blast. Inplace of the old enclosed nozzles, this novel non-clogging nozzle usesan open deflector plate mounted to intersect the liquid grit blast,preferably encroaching on the blast slightly and at an angle of to 15.

This application is a continuation-in-part of our copending applicationSer. No. 394,198, filed Sept. 3, 1964, now abandoned; which in turn wasa continuation-in-part application of Ser. No. 296,133, now issued asPatent No. 3,257,759, dated June 28, 1966.

This invention relates to a liquid blasting device assembly useful inhandling fluids having particulate matter entrained therein. Moreparticularly, this invention relates to an improved liquid blast meansespecially useful in handling abrasive slurries because of itsnon-clogging operational characteristics.

The utility of abrasive blasting as a method of conditioning the surfaceof metal parts is well established in the industrial arts. Commonlyowned, copending applications Ser. No. 296,133, filed July 18, 1963, byMillhiser et al., now issued as Patent No. 3,257,759, dated June 28,1966; and Ser. No. 117,444, filed June 15, 1961, by Millhiser, nowissued as Patent No. 3,237,351, dated Mar. 1, 1966, also discloseespecially advantageous surface reforming apparatus and processesutilizing liquid grit blasting therefor.

One problem which has existed in the prior art is recurrent clogging ofnozzles used for abrasive blasting. Another problem is the abrasiveeifect of the slurry on the nozzle surfaces. These problems haveheretofore made necessary a considerable amount of maintenance anddiminished the benefits derived from abrasive blasting operation.

Another problem is in adjusting the direction of a fixed blasting devicerelative to a fixed holder when these are out of alignment, mostcommonly due to the machine being used for treating a different partthan for that which it was originally designed This often happens when apart is redesigned for a model change or the part becomes obsolete. Inthe past, the resulting alignment requirements often involved extensiverefabrication often accompanied by costly drafting and engineeringstudy.

It is an object of the present invention to provide a blast assemblyuseful in handling slurries which assembly is relatively free fromclogging.

It is another object of the invention to provide a blast assembly thatis easily maintained.

t is a further object of the invention to provide a vomitory whereinabrasive damage is substantially limited to a single replaceable part.

It is still a further object of this invention to enable the directionof impingement from the fixed blasting device to be varied easily over asignificant range by a simple adjustment, replacement, or addition tothe blasting device capable of being performed by any service mechanic,thereby greatly increasing the flexibility and adaptability of theblasting device.

Applicants have met the foregoing objects by providing a unique blastassembly wherein an abrasive slurry is directed by a single, open tubeat a glancing angle against a deflecting surface rather than through anozzle which is subject to clogging.

If one of the inclined sides is removed, and the other positioned sothat, near the tip of the inclined plate, a portion of the liquid streamis engaged, a powerful ribbon shaped liquid flow results. The size andangle of the remaining side walls are such that this deflector extendsover the line of the projected axis of the blast tube area meeting atthe top. The resultant effect is a very excellent ribbon of abrasive andliquid travelling at a slight angle from the axis of the blast tubeproper.

Another advantageous feature of the instant invention is one wherebyparts of the vomitory subjected to wear may be independently removedfrom, and rapidly replaced in, the blasting assembly. Some embodimentsof the invention, because of low abrasive'nature of the slurries beinghandled therewith, will not require the removablepart feature.

Advantageously the deflecting surface is at a 5 to 15 degree angle inrelation to axial flow of blasting media through the blast tubes. Theplate forming the deflecting surface may conveniently be fixed in amanner so as to be not only demountable, but also be adjustable betweenthe 5 and 15 limits as is required for the particular use, which furtherdemonstrates its flexibility. Where the deflecting plate is used with asingle blast, the plate can also conveniently be rotated about the axisof the blast. In some applications it is desirable to have anoscillating blast sweep back and forth over or pulse on an area oftreatment. This invention readily lends itself to such a use byoscillating the deflecting plate back and forth in the blast stream.This could be accomplished by eccentric cams or the like.

In this application and accompanying drawings, we have shown anddescribed a preferred embodiment of our invention and have suggestedvarious alternatives and modifications thereof, but it is to beunderstood that these are not intended to be exhaustive and that otherchanges and modifications can be made within the scope of the invention,These are selected and included for purposes of illustration in orderthat others skilled in the art will more fully understand the inventionand the principles thereof and will be enabled to modify it and embodyit in a variety of forms, each as may be best suited to the conditionsof a particular case. 7

FIGURE 1 is a perspective view showing an abrasiveslurry-blastingassembly with the device of the instant invention embodied therein.

FIGURE 2 is a fragmentary elevational view of the apparatus of FIGURE 1,showing the relationship between blast tubes and manifold.

FIGURE 3 is a front end elevational view of a blasting 3 device of theinstant'invention. Holdingclips for the inclined plate arenot shown, forclarity.

FIGURE 4 is a plan View of a blast device of FIG URE 3.

FIGURE 5 is a side elevational view of the blast device of FIGURE 3.

FIGURE 6 is a side elevational view of the blast device shown attachedto the assembly of FIGURE 1.

FIGURE 7 is a front elevational view of the blast device shown in FIGURE6.

FIGURE 8 is a perspective view of a device embodying. a non-planarplate. 7

FIGURE 9 is an elevational view, partially in section of a jet-blastingapparatus utilizing three of the improved devices of the invention.

. FIGURE 10 is an elevational view from the side of the apparatus shownin FIGURE 9, showing additional detail of the slurry recirculationsystem.

FIGURE 11 is a side elevational view similar to FIG- URE 5 of anabrasive blast deflecting device adjustable between 5 and 15 and alsocapable of being oscillated therebetween.

Referring to FIGURES 1 and 2, the apparatus shown therein is partiallysubmerged, e.g., up to liquid level in a reservoir of liquid containingsuspended abrasive grit. A driving liquid under high pressure is led inthrough port 22 into and through manifold 24 and ejected through roundjet orifices 26 at a high velocity. Orifices 26 are spaced about oneinch from blast tubes 28 of larger internal diameter, into which thedriving liquid passes, entraining a considerable quantity of thegrit-laden liquid by its passage therethrough between the orifices 26and the tubes 28;

As seen in FIGURES 1 and 2, the outer ends of tubes 28 pass throughplate 32 and the foot 44 of deflector assembly 30, mounted on a frame(not otherwise shown in the drawing) by angle brackets 34. The liquidabrasive last emerges from blast tubes 28, at very high velocity,directed against the part to be treated, diagrammatically represented at37. A deflecting surface 36beyond the ends of blast tubes 28 isinterposed at a glancing angle so that the grit blast is deflectedslightly and concentrated, but with minimal reduction of velocity andminimal abrasion of the deflecting director 36.

Because this device uses a single glancing director plate, i.e., surface36, with no opposite side, large pieces of grit, grit agglomeration, orcontaminating solids cannot clog it. In the respective embodimentsdiscussed below, like elements are identified by the same referencenumbers plus the letter a, b, c, or d, respectively. For clarity, manyofthese elements are indicated in the drawingsof one embodiment but maynot be specifically mentioned in the discussion of each embodiment.

Another embodiment is shown in FIGURES 3-5.

This embodiment of the invention is so constructed that glancing plate36a may be removed easily and replaced, e.g., when it is desired to havea plate of a different configuration, for example a deflector assembly bwith a curvilinear detector plate 36b as illustrated in FIGURE 8 andalso fully described, in aforementioned Patent No.

Referring to FIGURES 3-5, plate 36a has welded thereon end members 40aand locating clips 46a, which are bolted to uprights 42a on base 44a bybolts 45a so as to securely position the plate 36a between uprights 42a.

FIGURES 6 and 7 show an enlarged view of the deflector plate 30including its base 44, ends 40, and the plate itself 36.

FIGURES 9 and 10 show apparatus mounted on a mounting frame 56 andenclosed in a housing 58 wherein the aforementioned blast devices areadvantageously utilized.

When the devices of the instant invention are used in combination with arotary table 62 on which the part to be blasted is carried, they areadvantageously mounted, as

'seen in FIGURE 9, with apart 37c placed so that the part clogged oldertype nozzles.

A is simultaneously cleaned from a variety of angles. The

part 370 is carried on rotating table 62 best seen in FIG- URE 10. Whenthe blasts are directed downward, as shown in FIGURE 9, the glancingplate 36 may advantageously be positioned on the upper side of theblast.

Short jet tubes 260 are utilized'in conveying the blasting media to theblats tubes 280 from feed manifolds 220. The longer blast tubes shown inFIGURE 1 are normally not required for the apparatus of FIGURES 9 and 10with its closer proximity of the manifolds 22s to the article beingtreated.

As seen in FIGURE 10, abrasive slurry is collected below table 62 andreturned to a feed hopper 68 from which it is supplied to blast tubes28c, and entrained by jets from the nozzles 26c. Return pipe 70 is usedin conducting the slurry ,-from a collector sump (not shown) beneath theparts 37c to the hoppers 68 via slurry. guide baflle- 72.

Below table 62 in FIGURE 10 is a screen 76 which is used to preventover-sized particles from being recirculated in the blast system; Priorart equipment required screening having one-quarter inch-squareapertures, because larger apertures would allow clogging of the priorart nozzles, and terminate, or destroy the eflicacy of, the blastingtreatment. Consequently, the build-up of foreign matter in the prior artapparatus became a problem and a considerable'amount of downtime wasrequired for cleaning the screens. With the present apparatus, muchlarger Blast tubes such as shown in FIGURE 1 at 28 conduct thegrit-containing liquid to ports 48a. Tapped holes 50a provide means forbolting the deflector assembly 30a to the blast tube assembly, forexample, as seen in FIG- 7 URE 1.

In the modification illustrated in FIGURE 11 the deflecting plate 36d ofthe deflector assembly 30d is made adjustable so that it can be set atany desiredangle, preferably between 5 and 15. The deflectorplate 36dcan be set at any desired angle by setting down the bolts 45d so as tobring the locating bar 86 (which is welded to the back of plate 36d)hard up against each respective upright 42d. Alternatively, thedeflector plate 36d can oscillate back and forth over a small angle togive an oscillating blast sweep. This can be accomplished by using thebolts 45d as pivots and an eccentric cam 80 (rotated by any conventionalmeans) which bears on the back of the deflector plate 36d. The force ofthe blast issuing from the blast tube 28a is normally suflicient to keepthe deflector plate 36d against cam 80; however, a biasing means may beemployed if desired. Also, a stop 82 may be used to position thedeflector plate 36d (if no biasing means is employed) to locate theplate 36d when no blast is issuing from the blast tube 28d. Any devicewhich might occur to those skilled in the art may be used to achieveoscillation of the deflector plate 36d in place of the cam 80.

We claim:

1. A liquid grit blast device comprising a blast tube for channeling anopen liquid grit blast therethrough, a deflecting plate positioned at aglancing angle to any blast issuing from said blast tube to deflect anddirect said blast, and mounting means to position said plate relative tosaid blast tube.

2. A device as claimed in claim 1 further comprising a row of blasttubes including said blast tube, which tubes are similar and aresubstantially aligned in parallel relationship, and said plate beingpositioned at a glancing angle to any blasts issuing from said blasttubes.

3. A device as claimed in claim 1 wherein said plate is at an angle offrom 5 to 15 degrees in relation to any blast issuing from said blasttube.

4. A device as claimed in claim 2 wherein said plate has a curvilinearform in transverse section relative to said blasts.

5. A device as claimed in claim 1 further including end members oneither side of said plate extending out from the deflecting surface ofsaid plate to contain the deflected blast from undue lateral spread.

6. A device as claimed in claim 1 wherein said mounting means detachablypositions said plate.

References Cited UNITED STATES PATENTS 108,408 10/1870 Tilghman 51-8LESTER M.

6 Tilghman 5111 X Gutmann 51-15 Umbricht 239521 Umbricht et al 51-8Millhiser 51-8 Millhiser 51-320 Millhiser et al. 51-319 SWINGLE, PrimaryExaminer.

